Endogenous neurosteroids regulate GABAA receptors through two discrete transmembrane sites
- PMID: 17108970
- DOI: 10.1038/nature05324
Endogenous neurosteroids regulate GABAA receptors through two discrete transmembrane sites
Abstract
Inhibitory neurotransmission mediated by GABA(A) receptors can be modulated by the endogenous neurosteroids, allopregnanolone and tetrahydro-deoxycorticosterone. Neurosteroids are synthesized de novo in the brain during stress, pregnancyand after ethanol consumption, and disrupted steroid regulation of GABAergic transmission is strongly implicated in several debilitating conditions such as panic disorder, major depression, schizophrenia, alcohol dependence and catamenial epilepsy. Determining how neurosteroids interact with the GABA(A) receptor is a prerequisite for understanding their physiological and pathophysiological roles in the brain. Here we identify two discrete binding sites in the receptor's transmembrane domains that mediate the potentiating and direct activation effects of neurosteroids. They potentiate GABA responses from a cavity formed by the alpha-subunit transmembrane domains, whereas direct receptor activation is initiated by interfacial residues between alpha and beta subunits and is enhanced by steroid binding to the potentiation site. Thus, significant receptor activation by neurosteroids relies on occupancy of both the activation and potentiation sites. These sites are highly conserved throughout the GABA(A )receptor family, and their identification provides a unique opportunity for the development of new therapeutic, neurosteroid-based ligands and transgenic disease models of neurosteroid dysfunction.
Similar articles
-
Analysis of Modulation of the ρ1 GABAA Receptor by Combinations of Inhibitory and Potentiating Neurosteroids Reveals Shared and Distinct Binding Sites.Mol Pharmacol. 2020 Oct;98(4):280-291. doi: 10.1124/mol.120.119842. Epub 2020 Jul 16. Mol Pharmacol. 2020. PMID: 32675382 Free PMC article.
-
Conserved site for neurosteroid modulation of GABA A receptors.Neuropharmacology. 2009 Jan;56(1):149-54. doi: 10.1016/j.neuropharm.2008.07.050. Epub 2008 Aug 13. Neuropharmacology. 2009. PMID: 18762201
-
Multiple roles for the first transmembrane domain of GABAA receptor subunits in neurosteroid modulation and spontaneous channel activity.Neurosci Lett. 2010 Apr 12;473(3):242-7. doi: 10.1016/j.neulet.2010.02.058. Epub 2010 Mar 1. Neurosci Lett. 2010. PMID: 20193738 Free PMC article.
-
Neurosteroid interactions with synaptic and extrasynaptic GABA(A) receptors: regulation of subunit plasticity, phasic and tonic inhibition, and neuronal network excitability.Psychopharmacology (Berl). 2013 Nov;230(2):151-88. doi: 10.1007/s00213-013-3276-5. Epub 2013 Sep 27. Psychopharmacology (Berl). 2013. PMID: 24071826 Free PMC article. Review.
-
Neurosteroid binding sites on GABA(A) receptors.Pharmacol Ther. 2007 Oct;116(1):7-19. doi: 10.1016/j.pharmthera.2007.03.011. Epub 2007 Apr 21. Pharmacol Ther. 2007. PMID: 17560657 Review.
Cited by
-
Functional Alternatives to Alcohol.Nutrients. 2022 Sep 13;14(18):3761. doi: 10.3390/nu14183761. Nutrients. 2022. PMID: 36145137 Free PMC article. Review.
-
Progesterone in the Brain: Hormone, Neurosteroid and Neuroprotectant.Int J Mol Sci. 2020 Jul 24;21(15):5271. doi: 10.3390/ijms21155271. Int J Mol Sci. 2020. PMID: 32722286 Free PMC article. Review.
-
Interfacial binding sites for cholesterol on GABAA receptors and competition with neurosteroids.Biophys J. 2021 Jul 6;120(13):2710-2722. doi: 10.1016/j.bpj.2021.05.009. Epub 2021 May 20. Biophys J. 2021. PMID: 34022235 Free PMC article.
-
Allosteric modulation by benzodiazepines of GABA-gated chloride channels of an identified insect motor neurone.Invert Neurosci. 2009 Nov;9(2):85-9. doi: 10.1007/s10158-009-0091-0. Epub 2009 Oct 22. Invert Neurosci. 2009. PMID: 19847463
-
Neurosteroid migration to intracellular compartments reduces steroid concentration in the membrane and diminishes GABA-A receptor potentiation.J Physiol. 2007 Nov 1;584(Pt 3):789-800. doi: 10.1113/jphysiol.2007.142794. Epub 2007 Aug 30. J Physiol. 2007. PMID: 17761771 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources